In recent years, as a standard for a disc type record medium detachable from a record and reproduction apparatus, Blu-ray Disc standard has been proposed. The Blu-ray Disc standard uses a disc as a record medium that has a diameter of 12 cm and that is coated with a cover layer having a thickness of 0.1 mm, a blue-purple laser having a wavelength of 405 nm, and an objective lens having a numerical aperture of 0.85 as optical systems. The Blu-ray Disc accomplishes a maximum of 27 GB record capacity that allows more than 2 hours of a Japanese BS digital high-vision broadcast program to be recorded without deterioration of picture quality.
It is expected that there will be AV (Audio/Video) signal sources that are analog signals and digital signals of for example analog television broadcast programs and digital television broadcast programs, respectively. In the Blu-ray Disc standard, sub-standards for methods of recording these broadcast programs have been established.
On the other hand, as a derivative standard of the current Blu-ray Disc standard, reproduction-only record mediums on which a movie, music, or the like is pre-recoded are being developed. Although DVDs (Digital Versatile Discs) have been widespread as disc-shaped record mediums on which a movie or music is pre-recorded, since reproduction-only optical discs based on the Blu-ray Disc standard feature a large capacity, high speed transfer rate, and so forth of the Blu-ray Disc standard and these discs have a record duration of two hours or longer of high-vision pictures with high picture quality, they are largely different from and superior to the existing DVDs. Hereinafter, the reproduction-only record mediums based on the Blu-ray Disc derivative standard is referred to as the BD-ROM (Blu-ray Disc-Read Only Memory) to distinguish them from the recordable Blu-ray Discs.
On the other hand, in the current Blu-ray Disc standard, user interface functions such as a method of displaying a list of video contents recorded on a disc, a function that displays a cursor on the list, and a function that allows the user to select a video content that he or she wants to reproduce have not been established. These functions are accomplished by a record and reproduction apparatus that records and reproduces data onto and from a Blu-ray Disc. Thus, the layout of the content list screen varies depending on the record and reproduction apparatus that reproduces the data. Thus, since there are also difference in user interfaces, they are not always user-friendly. For the reproduction-only discs, every reproduction apparatus need to accomplish user interfaces such as a menu screen as the disc (content) creator designed.
A multi-story function that displays a selection screen during reproduction of a video content and branches the main story to a sub-story depending on user's selection is generally referred to as the interactive function. To accomplish the interactive function, the disc creator needs to create a scenario that contains a reproduction sequence and branches that he or she designated, code the created scenario with a programming language, a script language, or the like, and record the program onto a disc. When the reproduction apparatus reads and executes the program, the apparatus can reproduce a video content and display a branch selection screen as the disc creator intended.
To accomplish the user interfaces as the disc creator intended, a method of generating a menu screen and a branch selection screen and a method of coding a process corresponding to user's input are required. However in the Blu-ray Disc standard (Blu-ray Disc Rewritable Format Ver 1.0), these methods have not been established. Thus, to date, it is difficult to cause every reproduction apparatus to reproduce a video content recorded on a Blue-ray Disc according to a scenario that the disc creator created regardless of the maker and model of the reproduction apparatus.
In addition, reproduction-only discs on which movies are pre-recorded need to have a subtitle display scheme. However, in the current Blu-ray Disc standard, the subtitle display scheme has not been established.
On the other hand, however, for example in the DVD (Digital Versatile Disc) standard, the foregoing interactive functions have been accomplished. For example, while a moving picture is being reproduced from a DVD-video, a menu screen is called with for example a remote control commander. By selecting a button displayed on the menu screen, the current scene can be changed to another scene. Moreover, in the DVD standard, a subtitle display scheme has been established. As the subtitle display scheme, one of a Japanese subtitle and an English subtitle that have been prepared can be selectively displayed.
In the case of the DVDs, the menu screen is composed of fixed sub picture data. When the menu screen is called, the sub picture data is composed with moving picture data and the combined data are displayed. Japanese Patent Application Laid-Open Publication No. HEI 10-308924 describes a structure that combines sub picture data with moving picture data and records the combined data onto a recordable DVD.
For the foregoing BD-ROMs, a technology that accomplishes a subtitle display and an interactive display has been proposed. In this technology, planes for a moving picture, a sub-picture (subtitle), and a menu are provided. The pictures of the three planes are combined into one picture. The combined picture is output.
According to this related art, a moving picture plane for a moving picture, a subtitle plane for a subtitle, and a graphics plane for a menu screen, buttons, and so forth are layered in the order so that the moving picture plane is the bottom plane and the graphics plane is the top plane. The subtitle plane is combined with the moving picture plane. The graphics plane is combined with the combined picture. When the subtitle plane and the graphics plane are combined, the opacity can be set on a pixel-by-pixel basis. When the opacity of a pixel of one plane is set at 0, a corresponding pixel of the next lower plane is displayed through the pixel of the upper plane.
The reproduction-only DB-ROMs need to have the so-called picture-in-picture function of which a small video picture is displayed in a large video picture.
In the picture-in-picture function, in a multi-angle picture composed of a plurality of pictures reproduced in the same time sequence, while a main angle picture is being displayed on a main screen, a second angle picture can be displayed on a sub screen that is a small area of the main screen.
When the picture-in-picture function is accomplished, it is necessary to provide a method of treating two video signals in parallel, combining pictures of these video signals, and displaying the combined picture on one screen.
In addition, when the picture-in-picture function is accomplished, a picture having a size of the main screen is reduced so that the reduced picture can be displayed in the sub screen. In many cases, the reduced picture and the main picture are combined and the combined picture is displayed. Thus, it is necessary to provide a method of supplying a reduced picture to a moving picture plane and combining the reduced picture and a moving picture.
In addition, it is necessary to provide a method of displaying a so-called wallpaper that is a picture of which a predetermined pattern is repeated in the background of reduced moving picture data.